There could be a storyline where Beerus, out of boredom, decides to train Goku Black instead of fighting him. But Goku Black misinterprets this as a sign of weakness and attacks Beerus. This could lead to a battle where Beerus has to hold back at first to avoid killing Goku Black, but as the fight progresses, he realizes he has to use his full power to subdue him.
One possible storyline could be that Naruto is somehow transported to Goku Black's universe. There, he has to face Goku Black who sees him as an intruder. Naruto would have to quickly learn about Goku Black's powers and find a way to fight back using his ninja skills. Another storyline could be that a powerful villain creates a rift between their two universes and pits them against each other. They start off as enemies but then realize they are being manipulated and team up to fight the real villain.
One possible storyline could be that Goku Black arrives on Earth in search of a powerful energy source. The Justice League detects his arrival and confronts him. At first, they underestimate his power. Goku Black easily defeats some of the members, but then the League starts to work together and figure out his weaknesses. Another storyline could be that an evil entity has brought Goku Black to the DC Universe to cause chaos and the Justice League has to stop him while also dealing with the entity. Or perhaps Goku Black is tricked into thinking the Justice League are enemies of the Saiyans and he attacks them, only to later find out the truth and have to team up with them to fight a greater threat.
In a 'Goku vs Beerus' fanfiction, it's really hard to say who would win. It could depend on how the author wants to write it. If the author wants to show Goku's growth, Goku might win through some new transformation or power - up. But Beerus is a powerful God of Destruction, so he also has a great chance of winning.
One possible storyline could be that Goku is accidentally transported to Alucard's world. They start off as enemies but then gradually learn about each other's powers and come to respect one another. Another could be that a powerful villain manipulates them into fighting each other. In this case, they might realize they are being used and team up against the real enemy.
One interesting plot twist could be that Goku and Beerus end up teaming up instead of fighting. Maybe they discover a common enemy that is even more powerful than them. Another could be that Beerus loses his power temporarily and Goku has to protect him from other villains while also trying to figure out how to return Beerus' power.
One possible storyline could be Goku Black's arrival in the RWBY universe causing chaos as his power level far exceeds that of most characters initially. He might target the powerful relics in the RWBY world, believing they could further his own dark ambitions.
One possible plotline could be that Broly, in his rage, accidentally provokes Beerus. Broly, not knowing who Beerus is, attacks him. Beerus, initially amused, decides to teach Broly a lesson but soon realizes that Broly's power is growing at an alarming rate. This leads to an intense battle where Broly pushes Beerus to use his full power. Another plotline could be that Beerus hears about Broly's power and decides to test him. He travels to Broly's location and challenges him. Broly, seeing Beerus as a threat to his friends or his planet, fights back with all his might.
In fanfiction, it's really hard to say for sure. Different fanfictions might have different outcomes. Some might make Goku Black super powerful and give him the win, while others would keep Beerus as the dominant force due to his status as a God of Destruction.
One possible storyline could be that Beerus and Supreme Kai have to team up to face a new, powerful enemy that threatens the universe. They start off not getting along well due to their different personalities, but as they fight together, they learn to respect each other's strengths and develop a friendship.
In 'Goku betrayed fanfiction', a common plot might be the corruption of his power. Let's say Goku discovers a new form of power that is seen as too dangerous by others. His friends and even some of the Z - fighters fear that he'll lose control and turn on them. So they decide to betray him first to protect the Earth. Another aspect could be a political betrayal. If there were some sort of intergalactic politics involved, Goku might be sacrificed or betrayed by his own side to make a deal with a more powerful alien race. And then there's the idea of a time - travel - related betrayal. Maybe someone from the future comes back and convinces everyone that Goku will cause a great disaster in the future, causing them to betray him in the present.